This is a application to conduct a randomized controlled trial of a 4-session behavioral intervention (Project Enhance) to reduce unsafe sexual practices among HIV-infected men who have sex with men (MSM) who are in care at Fenway Community Health (FCH). FCH is the largest provider of HIV care for MSM in New England and has seen an increase in STDs in recent years, signifying continued sexual risk taking in this population. The intervention, delivered by a trained medical social worker, will include education, motivational and behavioral skills enhancement, and will be individualized; participants will undergo an initial assessment and then choose from a set of modules that are most relevant to their needs. Participants who receive the intervention also will receive FCH's standard prevention case management (PCM) from a medical social worker including referrals to specific services they require. The comparison group will receive PCM alone. Consistent with NIH guidelines for intervention development, we propose a staged approach testing the intervention. Building on our qualitative data and experience with risk reduction counseling and interventions for at-risk HIV-uninfected individuals (e.g. Project EXPLORE! and HIV vaccine studies), we will pilot the intervention during a 6-month startup phase. The pilot will evaluate its acceptability, the feasibility of recruitment, and potential for clinically significant results. Sessions will be audio taped and rated, and we will solicit expert consultant feedback on the intervention approach, as well as participant feedback before beginning the efficacy trial. In the efficacy trial, primary HIV-care medical providers will inform participants of the study during their regularly scheduled visit. Interested participants will complete a prescreen assessment with a research assistant about sexual risk taking. Those participants who have engaged in sexual risk taking as defined by any unprotected anal intercourse (except that with a monogamous seroconcordant partner) in the past 3 months will be randomized to either PCM alone or PCM plus the 4-session individualized intervention (the enhanced condition). Participants will then be followed every three months for one year, integrating PCM and/or prevention booster sessions to their HIV care visits.